Allelopathy

Article By:

Ruddat, Manfred Department of Ecology and Evolution, University of Chicago, Chicago, Illinois.

Last reviewed:March 2020

DOI:https://doi.org/10.1036/1097-8542.024100

Show previous versions

• Allelopathy, published June 2014:Download PDF Get Adobe Acrobat Reader

A natural process in which harmful or beneficial effects are caused by secondary metabolites that spread from a donor organism to a recipient and are produced by plants, algae, bacteria, and fungi. Allelopathy is a key ecological process and has been studied predominantly in plants (Fig. 1). The chemical compounds involved in allelopathy are referred to as allelochemicals and comprise almost all classes of organic chemical substances. Hans Molisch (1937) coined the term allelopathy from the Greek words allelon for mutual and pathos for harm or affection, based on his observation of the premature ripening of apples and pears that were stored together with fruits from early ripening varieties. Depending on the purpose, the early ripening effect could be regarded as beneficial or harmful. Historically, detrimental effects have made botanists aware of allelopathy. One of the first accounts of an allelopathic effect that is commonly observed, namely the zone of growth inhibition around walnut trees (Juglans species), was reported by Pliny (23–79 CE). Even earlier, Theophrastus (372–287 BCE) described allelopathic effects of weeds on crop plants, including the inhibition of growth of alfalfa (Medicago sativa) by pigweed (Amaranthus retroflexus). See also: Agricultural science (plant); Agricultural soil and crop practices; Agriculture; Botany; Chemical ecology; Plant growth

The content above is only an excerpt.